'\" te
.\"  Copyright (c) 2004, Sun Microsystems, Inc. All Rights Reserved
.\" The contents of this file are subject to the terms of the Common Development and Distribution License (the "License").  You may not use this file except in compliance with the License.
.\" You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE or http://www.opensolaris.org/os/licensing.  See the License for the specific language governing permissions and limitations under the License.
.\" When distributing Covered Code, include this CDDL HEADER in each file and include the License file at usr/src/OPENSOLARIS.LICENSE.  If applicable, add the following below this CDDL HEADER, with the fields enclosed by brackets "[]" replaced with your own identifying information: Portions Copyright [yyyy] [name of copyright owner]
.TH ATTACH 9E "Jan 7, 2004"
.SH NAME
attach \- Attach a device to the system, or resume it
.SH SYNOPSIS
.nf
#include <sys/ddi.h>
#include <sys/sunddi.h>



\fBint prefix\fR\fBattach\fR(\fBdev_info_t *\fR\fIdip\fR, \fBddi_attach_cmd_t\fR \fIcmd\fR);
.fi

.SH INTERFACE LEVEL
illumos DDI specific (illumos DDI)
.SH PARAMETERS
.ne 2
.na
\fB\fIdip\fR\fR
.ad
.RS 7n
A pointer to the device's \fBdev_info\fR structure.
.RE

.sp
.ne 2
.na
\fB\fIcmd\fR\fR
.ad
.RS 7n
Attach type. Possible values are \fBDDI_ATTACH\fR and \fBDDI_RESUME\fR. Other
values are reserved. The driver must return \fBDDI_FAILURE\fR if reserved
values are passed to it.
.RE

.SH DESCRIPTION
The \fBattach\fR(9E) function is the device-specific initialization entry
point. This entry point is \fBrequired\fR and must be written.
.SS "DDI_ATTACH"
The \fBDDI_ATTACH\fR command must be provided in the \fBattach\fR(9E) entry
point. \fBDDI_ATTACH\fR is used to initialize a given device instance. When
\fBattach\fR(9E) is called with \fIcmd\fR set to \fBDDI_ATTACH\fR, all normal
kernel services (such as \fBkmem_alloc\fR(9F)) are available for use by the
driver. Device interrupts are not blocked when attaching a device to the
system.
.sp
.LP
The \fBattach\fR(9E) function is called once for each instance of the device on
the system with \fIcmd\fR set to \fBDDI_ATTACH\fR. Until \fBattach\fR(9E)
succeeds, the only driver entry point which may be called is \fBgetinfo\fR(9E).
See the \fIWriting Device Drivers\fR for more information. The instance number
may be obtained using \fBddi_get_instance\fR(9F).
.sp
.LP
At attach time, all components of a power-manageable device are assumed to be
at unknown levels. Before using the device, the driver needs to bring the
required component(s) to a known power level. The \fBpm_raise_power\fR(9F)
function can be used to set the power level of a component. This function must
not be called before data structures referenced in \fBpower\fR(9E) have been
initialized.
.SS "DDI_RESUME"
The \fBattach()\fR function may be called with \fIcmd\fR set to
\fBDDI_RESUME\fR after \fBdetach\fR(9E) has been successfully called with
\fIcmd\fR set to \fBDDI_SUSPEND\fR.
.sp
.LP
When called with \fIcmd\fR set to \fBDDI_RESUME\fR, \fBattach()\fR must restore
the hardware state of a device (power may have been removed from the device),
allow pending requests to continue, and service new requests. In this case, the
driver must not make any assumptions about the state of the hardware, but must
restore the state of the device except for the power level of components.
.sp
.LP
If the device driver uses the automatic device Power Management interfaces
(driver exports the \fBpm-components\fR(9P) property), the Power Management
framework sets its notion of the power level of each component of a device to
\fBunknown\fR while processing a \fBDDI_RESUME\fR command.
.sp
.LP
The driver can deal with components during \fBDDI_RESUME\fR in one of the
following ways:
.RS +4
.TP
1.
If the driver can determine the power level of the component without having
to power it up (for example, by calling \fBddi_peek\fR(9F) or some other
device-specific method) then it should notify the power level to the framework
by calling \fBpm_power_has_changed\fR(9F).
.RE
.RS +4
.TP
2.
The driver must also set its own notion of the power level of the component
to \fBunknown\fR. The system will consider the component idle or busy based on
the most recent call to \fBpm_idle_component\fR(9F) or
\fBpm_busy_component\fR(9F) for that component. If the component is idle for
sufficient time, the framework will call into the driver's \fBpower\fR(9E)
entry point to turn the component off. If the driver needs to access the
device, then it must call \fBpm_raise_power\fR(9F) to bring the component up to
the level needed for the device access to succeed. The driver must honor any
request to set the power level of the component, since it cannot make any
assumption about what power level the component has (or it should have called
\fBpm_power_has_changed\fR(9F) as outlined above). As a special case of this,
the driver may bring the component to a known state because it wants to perform
an operation on the device as part of its \fBDDI_RESUME\fR processing (such as
loading firmware so that it can detect hot-plug events).
.RE
.SH RETURN VALUES
The \fBattach()\fR function returns:
.sp
.ne 2
.na
\fB\fBDDI_SUCCESS\fR\fR
.ad
.RS 15n
Successful completion
.RE

.sp
.ne 2
.na
\fB\fBDDI_FAILURE\fR\fR
.ad
.RS 15n
Operation failed
.RE

.SH ATTRIBUTES
See \fBattributes\fR(7) for descriptions of the following attributes:
.sp

.sp
.TS
box;
c | c
l | l .
ATTRIBUTE TYPE	ATTRIBUTE VALUE
_
Interface Stability	Committed
.TE

.SH SEE ALSO
.BR cpr (4),
.BR pm (4D),
.BR detach (9E),
.BR getinfo (9E),
.BR identify (9E),
.BR open (9E),
.BR power (9E),
.BR probe (9E),
.BR ddi_add_intr (9F),
.BR ddi_create_minor_node (9F),
.BR ddi_get_instance (9F),
.BR ddi_map_regs (9F),
.BR kmem_alloc (9F),
.BR pm_raise_power (9F),
.BR pm (9P),
.BR pm-components (9P)
.sp
.LP
\fIWriting Device Drivers\fR
